电子课本网 › 第123页

第123页

信息发布者：

1724

0.37

800

$\frac{1}{3}$

$\frac{27}{25}$

$1\frac 35$

$ \frac {13}{15}$

514.8

$\begin {aligned}&756\div (2×158 - 309)\\=&756\div (316 - 309)\\=&756\div 7\\=&108\end {aligned}$

$\begin {aligned}&\frac {7}{24}\div (\frac {5}{6}-\frac {3}{4})×\frac {3}{14}\\=&\frac {7}{24}\div \frac {1}{12}×\frac {3}{14}\\=&\frac {7}{2}×\frac {3}{14}\\=&\frac {3}{4}\end {aligned}$

$ \begin {aligned}&18.5-(5.5 + 4.9)\div 1.3\\=&18.5 - 10.4\div 1.3\\=&18.5 - 8\\=&10.5\end {aligned}$

解：

$ \begin {aligned}x - 35\%x&=0.52\\0.65x&=0.52\\x &=0.52\div 0.65\\x &=0.8\end {aligned}$

解：

$\begin {aligned}\frac {1}{9}：\frac {1}{18}&=9：x\\\frac {1}{9}x&=\frac {1}{18}×9\\\frac {1}{9}x&=\frac {1}{2}\\x &=\frac {1}{2}\div \frac {1}{9}\\x &=4.5\end {aligned}$

1：4

$ $选条件$ (2)$

$36\div 80\%×(1 - 80\%) = 9($人$)$

答：错误的有$9$人。